Ignition interrupter



April 6, 1954 H. R. KITTS IGNITION INTERRUPTER Filed March 26, 1951 IN VEN TOR.

HriR/P) Fr? 7 75 BY a multiple-spark Patented Apr. 6, 1954 UNITED STATES PATENT OFFICE IGNITION INTERRUPTER Harry R. Kitts, Green Bay, Wis.

Application March 26, 1951, Serial No. 217,564

'overcome these advantages by applying several spark plugs to a cylinder, or by providing aninterrupting device with several sets of breaker points whose main function is to provide a sucsession of distinct sparks for each gas charge in each cylinder, so that if one spark will not cause full and complete combustion, a second or followup spark will complete the combustion.

These solutions have not been practical because of their complexity and resulting inadaptability to the present day standardized ignition I system designs.

The purpose of this invention is to provide a multiple-spark ignition interrupter apparatus, capable of providing a succession of sparks for each gas charge in each cylinder, embodying only a few additional simple and efficient parts which can be readily assembled and applied to conventional standardized automobile ignition systems without requiring any changes in the construction, arrangement or design of said conventional system.

An object of this invention is to provide a multiple-spark ignition system interrupter that is very easily adapted to the conventional standardized ignition apparatus.

Another object of this invention is to provide ignition system interrupter that is interchangeable with the conventional interrupters presently used. Still another object of this invention is to provide a multiple-spark ignition system that is controlled by one main breaker arm structure.

Yet another object of this invention is to provide a multiple-spark ignition system interrupter having a main breaker arm and auxiliary breaker arm means mounted thereon for actuation therebreaker points connected therewith.

Yet a further object of this invention is to provide. a multiple-spark ignition interrupter Claims. (Cl. 2i)0--31) structure which supplies a follow-up spark at a fixed crank angle relation to the normal basic spark regardless of wear of a common cam follower.

Another object of this invention is to provide a multiple-spark interrupter that does not bounce at high speeds.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

Figs. 1 and 2 illustrate front elevational views of the interrupter structure and cam showing different relative positions of the elements of the mechanisms;

Fig. 3 is an enlarged sectional view taken alon line 3-3 of Fig. 1; and

Fig. 4 is an electrical diagram showing the circuit connections of the interrupter embodied in a conventional simplified ignition system.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 an interrupter device generally indicated by reference numeral 9, comprising a plate or disc It, preferably made of an insulating material, which is adapted to be rotatably controlled by governor means, mechanical or vacuous, or the like (not shown), to effect an automatic advance or retard of the sparking, in the conventional auto ignition system manner. Said disc I0 is centrally apertured to receive a distributor or cam shaft ll therethrough, to which a hexagonal cam I2 is rotatively-rigid secured and about which the disc is revolvable for ignition timing purposes, in the conventional ignition system manner. The six angle point portions of said cam serve as cam lobes.

A first main breaker arm i3 is pivotally connected at one end, to disc It as by means of pin [4 fixed to disc Ill; the other end of said arm is provided with a contact point I5 secured thereto as by spot welding. Intermediate the ends of said arm is riveted a cam follower or rubbing block l6 which is disposed to slidably contact the cam l2.

Arm I3 is biased toward cam l2 by means of initially tensioned leaf spring I? having one end riveted to the under side of arm l3 and the other end abutting against a fixed bracket i8 secured to disc It 'by means of screw 19. The spring I! is held in abutment against the bracket by means of an elongated bolt 2| and nut 22. A thumb screw 23 is threadedly engaged with the free end a of said bolt to provide a binding post arrangement generally indicated at 20 for the connection 3 forming one side of an ignition system shown in Fig. 4.

A second bracket 24, preferably conductive, is secured to the disc H) by means of screws and 26. Elongated screw openings 48' are provided in said bracket to allow for bracket positional adjustability in aid of contact point gap settings hereinafter described. Said bracket 24 has a conductive, integrally formed arm 27 which supports a fixed contact point 28 secured thereto as by spot welding. Said contact point 28 is operatively disposed relative to companion contact point l5.

Movable contact point |5 is normally held in engagement with fixed contact point 28 by means .of cam I2.

Thus far the structure described is known to be old and conventional; the improvement thereonfollows.

A second auxiliary limb or breaker arm 29 is cantilever supported on the back of arm |3 and disposed in the same radial general direction therewith; one end being fixed thereto as by spot welding and the other free ascending upwardly and being spaced therefrom. Said second arm 29 should preferably have elastic and resilient characteristicssuch asa leaf spring or the like. A contact point 3| is secured to the free end of arm 29 as by spot welding.

'A cooperative fixed contact point 32, disposed to coact with movable contact point 3| and nora. mal1y spaced therefrom, is mounted as b spot welding on a conductive supporting element 33 which in turn is bolted to bracket 24 by means of an elongated bolt 34 and nut 35. The bolt .opening (not shown) through supporting element 33 is elongated to allow for some degree of positional adjustability of element 33 and its attachedcontact point 32. .A thumb screw 36 is .threadedly engaged on the free end of said bolt .34 to provide another binding post arrangement generally indicated at 39 for the connection thereto of an electrical conductor such as that forming the other side of the ignition system shown in Fig. 4.

An L-shaped bracket 31, having one leg riveted to arm 13 and the other leg disposed toward and beyond the arm 29, carries a cam screw 38 disposed over arm 29. Said screw is threadedly engaged with said bracket and is disposed so that its cam head bears against the outer face of arm 29 for adjusting the air gap between associated contact points 3| and 32. A coil spring .39 is interposed between the supporting bracket 31 and the head of cam screw 38 to resist rota- .tional displacement thereof.

Leaf spring arm 29 is preferably initially tensioned to normally bear against thecam 38. It is obvious that arotation of. cam screw 38 varies the airgap between cooperative contacts 3| and "32 through means of resilient limb 29.

,It is to be noted that the relation of the cam 38 to the arm 29 is such that a clockwisemovement of arm l3 will positively draw arm 29 clockwise along with it. In a counterclockwise movement there isno such positive drive connection.

4 This arrangement provides yieldable connecting means operative to normally limit relative movement of the limbs away from each other. but permitting free relative movement toward each other.

Fig. 4 shows a simplified wiring diagram of a. conventional auto ignition system comprising two circuits-primary and secondary.

The primary is a low voltage ignition circuit energized by a generator 4| and a battery 42 in the usual manner. In series therewith is the primary coil 43 and the interrupter 9. A condenser 44 is connected across the contact points of the interrupter 9 to prevent arcing thereacross.

The secondary high voltage circuit consists of a series arrangement of the secondary coil 45, inductively related to said primary coil 43, and an associated distributor adapted to be connected to spark plugs (not shown).

Operation: Assume the interrupter device to be connected in an ignition circuit as shown in Fig. l, and further assume the cam member to rotate in the direction indicated by the arrow. In the normal position of rest shown in Figs. 1 and 4, the primary circuit is closed through abutting main breaker contacts l5 and 2B and the primary induction coil 43 is being properly saturated.

As the cam travels clockwise from this normal position the cam lobe 4| initially will raise arm I3 and disengage main breaker points l5 and 23 thereby opening the primary circuit. As a result thereof, the magneticfield built-up around coil 43 collapses rapidly. The rapid movementv of collapsing lines of magnetic force induces a very high voltage in the secondary coil 45. This voltage is led to the distributor 46 where it directs the high voltage impulse first to one spark plug, then to another, and so on. The voltage being great enough to overcome the resistance at the gap between the spark electrodes, the circuit is completed to ground and the hot spark ignites the fuel mixture. The high voltage induced in this manner is momentary; and a surge occurs each time the magnetic field, established by current fiow through the primary circuit, is rapidly collapsed.

Shortly after the breaking of associated breaker points l5 and 29, and before the high point on the lobe 41 is reached, cooperative breaker points 3| and 32 engage and close the primary circuit therethrough. This positionment of components is illustrated in Fig. 2. Theclosing of the primary circuit by these auxiliary points results in a current fiow through primary coil 43 and a build-up of a magnetic field around it.

As the cam travel continues to the high'point on the lobe 41, arm I3 continues to be raised, but arm'29 apparently is arrested because of the abutment of its auxiliary breaker points3| and 32.

However, due to the resilient characteristics of arm 29 it deflects'and bends, thereby allowing the full cam lift to operate without breakage of any of the associated components. In other words the cam continues topush-up andstress arm 29 to maintain engagementof contacts 3| and 32 for a preselected interval of time. Furthermore, it prevents bouncing of the resiliently mounted contact "3| against fixed contact 32.

It is to be-noted that immediately after'auxiliary breaker points 3| and 32 engage, any'further cam travel toward its high point progressively separates the cam screw 38* from its abutment with arm 29.

As the cam follower l6 moves down the other side of the cam lobe, from the high'point thereon, said deflection and bending is slowly relieved until cam screw 38 again abuts auxiliary arm 29, at which time'the deflection is fully relieved.

Continued motion down the cam results in a disengagement of the auxiliary breaker points 3! and 32 through means of the positive drive connection of the cam screw 38 against auxiliary arm 29. 1 a

The disengagement of auxiliary breaker points 3| and 32 results in a breaking of the primary circuit. Consequently, the magnetic field built up around coil 43 collapses rapidly and induces a high voltage pulse in the secondary coil 45. This pulse is made available to the spark plugs as described above.

A further travel of the cam results in the restoration of the associated mechanism elements to their original normal position shown in Fig. 1, wherein breaker points l5 and 28 are re-engaged in preparation for another saturation of primary coil 43.

This cycle of events is repetitive.

It is preferred that the cam and the associated interrupter components be space related so that the auxiliary or second spark follows the main spark by approximately degrees of crank angle. It is to be noted that the interval of time allowed for the coil build-up attendant to the sec-- ond spark is measured by the time lapse between the make and the break of coacting contact points 3| and 32. during which the cam lobe exerts a bending influence on arm 29 as when the follower moves upwardly on one side of the cam, commencing from a point corresponding to the engagement of auxiliary breaker points 3| and 32, thence over the high point of the cam, and thence downwardly on the other side of the cam to a point corresponding to the disengagement of said contact points 3| and 32.

It is preferred that the cam and the associated interrupter components be space related so that this coil build-up time interval is approximately 15 degrees of crank angle. This permits a sufficiently long period of closure to insure proper saturation of the induction coil to give a proper second spark.

When this improved interrupter arm mechanism is substituted for the interrupter mechanism .in the conventional interrupter, it has been found that substantially proper time and space relations are achieved by adjusting supporting bracket 24, downwardly, until ten thousandths (0.010) inch obtains between the cam and its follower when the apparatus is in its normal position of rest as shown in Fig. 1.

The characteristic features of this improved multiple-spark interrupter are, a structure that is very easily adapted to the conventional ignition apparatus; an interrupter structure that-is in- .terchangeable with the conventional interrupter without effecting. the design, operation or function of said conventional interrupter; a multiple limb interrupter arm that is controlled by one main -breaker arm; and finally an interrupter structurewhich supplies a follow-up spark at a fixed crank angle relation to the normalbasic sparkjregardless of wear of the common cam 'follower. I I

I Obviously many modifications and variations of the present invention are possiblein the light of In other words, it is the time lapse the above teachings. It is therefore to be under stood, that within the scope of the appended claims, the invention may be practised otherwise than as specifically described.

- What is claimed and desired to be protected by Letters Patent of the United States is:

1. An interrupter, comprising: an interrupter arm'comprising two spaced limbs one of which is resilient; a contact on each of said limbs; electrically connected fixed contacts operatively disposed relative to said aforementioned contacts, a set of cooperative contacts being normally engaged and another set of cooperative contacts being normally spaced; means interconnecting said limbs operative to normally limit relative movement of the limbs away from each other but permitting free relative movement toward each other; and means for actuating said interrupter arm, said actuating means being adapted to maintail an engagement between the cooperative contacts identified with the resilient limb for a preselected interval of time.

2. An interrupter, comprising: a first interrupter arm carrying a contact; a second resilient interrupter arm carrying a contact, mounted on said first interrupter arm in spaced relation thereto; a supporting member; a pair of electrically connected fixed contacts mounted on said supporting member and operatively disposed relative to said aforementioned contacts, the fixed contact associated with the first arm contact being normally engaged therewith, and the fixed contact associated with second arm contact being normally spaced therefrom; means interconnecting said first and second interrupter arms operativeto normally limit the spaced relation therebetween but permitting a free relative movement toward each other; and means for actuating said combined arm structure; said actuating means being adapted to continue to drive said structure after the second arm contact engages with its associated fixed contact.

3. An interrupter, comprising: a first interrupter arm carrying a contact; a second resilient interrupter arm carrying a contact, mounted on said first arm in spaced relation thereabove; a supporting member; a pair of electrically connected fixed contacts mounted on said supporting member and operatively disposed relative to said aforementioned contacts, the set of associated contacts identified with the first arm being normally engaged, and the set of associated contacts identified with the second arm being normally spaced; control means supported by said first arm operative to normally limit the spaced relation of said arms, but permitting free relative movement of the arms toward each other; and means for actuating said combined arm struc-v ture, said actuating means being adapted to maintain an engagement between the associated contacts identified with the second arm for an interval of time.

4. An interrupter, comprising: a first interrupter arm carrying a contact; a second resilient interrupter arm carrying a contact, mounted on said first arm and having its free end disposed in spaced relation above the free end ofsaid first arm; a supporting member; a pair of electrically connected fixed contacts mounted on'said supporting member operatively disposed relative to said aforementioned contacts, the set of associated contacts identified with the first arm being normally engaged, and the set of associated contacts identified with the resilient arm being normally spaced; control means mounted on said first arm operative to normally limit the maximum spaced relation between said arms but permitting a free movement of the resilient arm toward the first arm, said resilient arm being tensioned against said control means; and means for actuating said first arm, said actuating means being adapted to maintain an engagement between the associated contacts identified with the resillent arm for a preselectedinterval of time. 35. An interrupter, comprising; a first interrupter armcarrying a contact; a second resilient interrupter arm carrying a contact, mounted on said-first arm in ascending spaced relation thereoverga conductive supporting member; a pair of fixed contacts mounted on said supporting member operatively disposed relative to said aforementioned contacts, the set of associated contacts identified with the first arm being normally engaged, and the set of associated contacts identified-with the resilient arm being normally spaced; a, supporting element mounted on said first arm; a first cam mounted on said supporting element and disposed to engage with the top face side of the resilient arm and operative to vary the spaced relation between said first and resilient arm, said resilient arm being initially tensioned against said cam; and second cam means for actuating said first arm, said second cam means being adapted to maintain an engagement between the associated contacts identified with the resilient arm for a preselected interval of time. 7

6. An interrupter, comprising: a first interrupter arm carrying a contact; a second resilient interrupter armcarrying a contact, mounted on said first arm radially thereover; an adjustable conductive supporting member; a pair of fixed contacts mounted on said supporting member operatively disposed relative to said aforementioned contacts, the set of associated contacts identified with the first arm being normallyen- ,gaged, and the set of associated contacts identified with the resilient arm being normally spaced; a supporting element mounted on said first arm; a first cam rotatably mounted on said supporting element and disposed to bear against the top face of the resilient arm and operative to adjust the spaced relation between said first and resilient arms, said resilient arm being. initially tensioned against said cam; and a secondcam for actuating said first arm, said second cam being constructed and arranged to control anengagement between the associated contacts identified with the resilieritarm for a preselected interval of time.

' 7. An interrupter arm,-comprising: a pivotal arm; a second resilient arm having one end supported on said pivotal arm and the other end spaced therefrom, each carrying a contact; and second contacts adapted to. be operatively disposed relativeto said. aforementioned contacts, a set of cooperative contacts being normally engaged and another set of cooperative contacts being normally spaced.

8. An interrupter arm, comprising: a pivotal arm; asecond resilient arm cantilever mounted .on said pivotal arm; a contact on each of said arms; and-second contacts adapted to be opera- .tively disposed relative to said aforementioned contacts, a set of cooperative contacts being normally engaged and another set of cooperative contacts being normally spaced.

' v.9. An interrupter arm, comprising: a pivotal arm; a, second resilient arm having one end mounted on said pivotal arm and the remaining portion of. said resilient arm disposed in diverging spaced relation to saidpivotal arm; a contact 8 on each of said arms; and second contacts adapted to be operatively disposed relative to said aforementioned contacts, a set of cooperative contacts being normally engaged and another set or cooperative contacts being normally spaced.

.10. An interrupter arm, comprising: a pivotal arm; a second resilient arm having one end mounted on the back of said pivotal arm and the remaining portion of said resilient arm disposed in ascending spaced relation above said pivotal arm; a contact on each of said arms; and second contacts adapted to be operatively disposed relative to said aforementioned contacts, a set of cooperative contacts being normally engaged and another set of cooperative contacts being normally spaced.

11. The apparatus of claim 8 and means extending from one of said arms engageable with the other of said arms operative to normally limit relative movement of the arms away from each other but permitting free relative movement toward each other.

12. The apparatus of claim 9 and means extending from said pivotal arm engageable with said resilient arm operative to normally limit relative movement of said arms away from each other but permitting movement toward each other.

13. The apparatus of claim 10 and an extension of said pivotal arm engageable with said resilient arm operative to normally limit relative movement of said arms away from each other but permitting free movement toward eachother.

14. An interrupter arm, comprising: a first interrupter arm carying a contact; a second resilient arm carrying a contact, mounted on the back of said first arm and-having its free end disposed in spaced relation above the free end of said first arm; a supporting member; a pair of electrically connected fixed contacts mounted on said supporting member and operatively disposed relative to said aforementioned'contacts, the set of associated contacts identified with the first arm being normally engaged, and the set of associated contacts identified with the resilient arm being normally spaced; a supporting element mounted on said first arm; and a cam mounted 'on saidsupporting element and disposed to engage with the top side of the resilient arm and operative to adjust the spaced relation between said first and resilient arms.

15. An interrupter comprising: an interrupter arm comprising two spaced limbs one of which is resiliently movable relative to the other, a contact on each of said limbs, fixed contacts operatively disposed relative to said aforementioned contacts, a set of cooperative contacts being normally engaged and another set of cooperative contacts being normally spaced, means interconnecting said limbs operative to normally limit relative movementof the limbs away from each other but permitting relative movement toward each other, and means for actuating said interrupter arm, said actuating means being adapted to maintain an engagement between the cooperative contacts identified with the resilient limb for a preselected interval of time.

"Rcfercnces cited in the flle of this patent UNITED STATES PATENTS Number Name Date 902,783 Varley Now-3,1908 1,576,222 .Robbins "Mar. 9,19% 1,914,231 Armstrong June13. 1933 

